package com.sun.gluegen.cgram;

import antlr.collections.AST;
import antlr.CommonAST;
import antlr.Token;
import java.lang.reflect.*;
import java.util.Hashtable;
import java.util.Enumeration;

/** 
  Class TNode is an implementation of the AST interface
  and adds many useful features:

  It is double-linked for reverse searching.
  (this is currently incomplete, in that method doubleLink() must
  be called after any changes to the tree to maintain the 
  reverse links).

  It can store a definition node (defNode), so that nodes such
  as scoped names can refer to the node that defines the name.

  It stores line numbers for nodes.

  Searches for parents and children of a tree can be done
  based on their type.

  The tree can be printed to System.out using a lisp-style syntax.



 */
public class TNode extends CommonAST {
  protected int ttype;
  protected String text;
  protected int lineNum = 0;
  protected TNode defNode;
  protected TNode up;
  protected TNode left;
  protected boolean marker = false;
  protected Hashtable attributes = null;
  static String tokenVocabulary;  
  



  /** Set the token vocabulary to a tokentypes class
      generated by antlr.
  */
  public static void setTokenVocabulary(String s) {
    tokenVocabulary = s;
  }

    
public void initialize(Token token) {
        CToken tok = (CToken) token;
        setText(tok.getText());
        setType(tok.getType());
        setLineNum(tok.getLine());
        setAttribute("source", tok.getSource());
        setAttribute("tokenNumber", new Integer(tok.getTokenNumber()));
}       
public void initialize(AST tr) {
        TNode t = (TNode) tr;
        setText(t.getText());
        setType(t.getType());
        setLineNum(t.getLineNum());
        setDefNode(t.getDefNode());
        this.attributes = t.getAttributesTable();
}       


  /** Get the token type for this node */
  public int getType() { return ttype; }
  
  /** Set the token type for this node */
  public void setType(int ttype_) { 
    ttype = ttype_; 
  }
  
  /** Get the marker value for this node.
   This member is a general-use marker.
   */
  public boolean getMarker() { return marker; }
  
  /** Set the marker value for this node.
   This property is a general-use boolean marker.
   */
  public void setMarker(boolean marker_) { 
    marker = marker_; 
  }

  /** get the hashtable that holds attribute values.
   */  
  public Hashtable getAttributesTable() {
    if(attributes == null)
      attributes = new Hashtable(7);
    return attributes;
  }

  /** set an attribute in the attribute table.
   */
  public void setAttribute(String attrName, Object value) {
    if(attributes == null)
      attributes = new Hashtable(7);
    attributes.put(attrName,value);
  }

  /** lookup the attribute name in the attribute table.
    If the value does not exist, it returns null.
    */
  public Object getAttribute(String attrName) {
    if(attributes == null)
      return null;
    else
      return attributes.get(attrName);
  }

  /** Get the line number for this node.
   If the line number is 0, search for a non-zero line num among children */
  public int getLineNum() { 
    if(lineNum != 0)
      return lineNum; 
    else
      if(down == null)
        return lineNum; 
      else
        return ((TNode)down).getLocalLineNum();
  }
  
  public int getLocalLineNum() { 
    if(lineNum != 0)
      return lineNum; 
    else
      if(down == null)
        if(right == null)
          return lineNum; 
        else
          return ((TNode)right).getLocalLineNum();
      else
        return ((TNode)down).getLocalLineNum();
  }
  
  /** Set the line number for this node */
  public void setLineNum(int lineNum_) { 
    lineNum = lineNum_; 
  }
  
  /** Get the token text for this node */
  public String getText() { return text; }
  
  /** Set the token text for this node */
  public void setText(String text_) { 
    text = text_; 
  }
  
  /** return the last child of this node, or null if there is none */
  public TNode getLastChild() {
    TNode down = (TNode)getFirstChild();
    if(down != null)
      return down.getLastSibling(); 
    else 
      return null;
  }

  /** return the last sibling of this node, which is 
      this if the next sibling is null */
  public TNode getLastSibling() {
    TNode next = (TNode)getNextSibling();
    if(next != null)
      return next.getLastSibling();
    else
      return this;
  }

  /** return the first sibling of this node, which is 
      this if the prev sibling is null */
  public TNode getFirstSibling() {
    TNode prev = (TNode)left;
    if(prev != null)
      return prev.getFirstSibling();
    else
      return this;
  }


  /** return the parent node of this node */
  public TNode getParent() {
    return (TNode)getFirstSibling().up;
  }


  /** add the new node as a new sibling, inserting it ahead of any
    existing next sibling.  This method maintains double-linking.
    if node is null, nothing happens.  If the node has siblings, 
    then they are added in as well.
    */
  public void addSibling(AST node) {
    if(node == null) return;
    TNode next = (TNode)right;
    right = (TNode)node;
    ((TNode)node).left = this;
    TNode nodeLastSib = ((TNode)node).getLastSibling();
    nodeLastSib.right = next;
    if(next != null)
      next.left = nodeLastSib;
  }

 
  /** return the number of children of this node */
  public int numberOfChildren() {
    int count = 0;
    AST child = getFirstChild();
    while(child != null) {
      count++;
      child = child.getNextSibling();
    }
    return count;
  }


  /** remove this node from the tree, resetting sibling and parent
    pointers as necessary.  This method maintains double-linking */
  public void removeSelf() {
    TNode parent = (TNode)up;
    TNode prev = (TNode)left;
    TNode next = (TNode)right;
     
    if(parent != null) { 
      parent.down = next;
      if(next != null) {
        next.up = parent;
        next.left = prev;    // which should be null
      }
    } 
    else {      
     if(prev != null)
      prev.right = next;
     if(next != null)
       next.left = prev;
    }
  }


  /** return the def node for this node */
  public TNode getDefNode() {
      return defNode;
  }
  
  /** set the def node for this node */
  public void setDefNode(TNode n) {
    defNode = n;
  }


  /** return a deep copy of this node, and all sub nodes.
    New tree is doubleLinked, with no parent or siblings.
    Marker value is not copied!
    */
  public TNode deepCopy() {
    TNode copy = new TNode();
    copy.ttype = ttype;
    copy.text = text;
    copy.lineNum = lineNum;
    copy.defNode = defNode;
    if(attributes != null)
      copy.attributes = (Hashtable)attributes.clone();
    if(down != null)
      copy.down = ((TNode)down).deepCopyWithRightSiblings();
    copy.doubleLink();
    return copy;
  }


  /** return a deep copy of this node, all sub nodes,
    and right siblings.
    New tree is doubleLinked, with no parent or left siblings.
    defNode is not copied  */
  public TNode deepCopyWithRightSiblings() {
    TNode copy = new TNode();
    copy.ttype = ttype;
    copy.text = text;
    copy.lineNum = lineNum;
    copy.defNode = defNode;
    if(attributes != null)
      copy.attributes = (Hashtable)attributes.clone();
    if(down != null)
      copy.down = ((TNode)down).deepCopyWithRightSiblings();
    if(right != null)
      copy.right = ((TNode)right).deepCopyWithRightSiblings();
    copy.doubleLink();
    return copy;
  }


  /** return a short string representation of the node */
  public String toString() {
    StringBuffer str = new StringBuffer( getNameForType(getType()) +
           "[" + getText() + ", " + "]");

     if(this.getLineNum() != 0) 
       str.append(" line:" + (this.getLineNum() ) );

     Enumeration keys = (this.getAttributesTable().keys());
     while (keys.hasMoreElements()) {
       String key = (String) keys.nextElement();
       str.append(" " + key + ":" + (this.getAttribute(key)));
     }

    return str.toString();
  }


  /** print given tree to System.out */
  public static void printTree(AST t) {
       if (t == null) return;
       printASTNode(t,0);
       System.out.print("\n");
  }


  /** protected method that does the work of printing */
  protected static void printASTNode(AST t, int indent) {
     AST child1, next;
     child1 = t.getFirstChild();         

    System.out.print("\n");
     for(int i = 0; i < indent; i++) 
       System.out.print("   ");

     if(child1 != null) 
        System.out.print("(");

     String s = t.getText();
     if(s != null && s.length() > 0) {
       System.out.print(getNameForType(t.getType()));
       System.out.print(": \"" + s + "\"");
     }  
     else
       System.out.print(getNameForType(t.getType()));
     if(((TNode)t).getLineNum() != 0) 
       System.out.print(" line:" + ((TNode)t).getLineNum() );

     Enumeration keys = ((TNode)t).getAttributesTable().keys();
     while (keys.hasMoreElements()) {
       String key = (String) keys.nextElement();
       System.out.print(" " + key + ":" + ((TNode)t).getAttribute(key));
     }
     TNode def = ((TNode)t).getDefNode();
     if(def != null)
       System.out.print("[" + getNameForType(def.getType()) + "]");


     if(child1 != null) {
        printASTNode(child1,indent + 1);

        System.out.print("\n");
        for(int i = 0; i < indent; i++) 
           System.out.print("   ");
        System.out.print(")");
     }

     next = t.getNextSibling();
     if(next != null) {
        printASTNode(next,indent);
     }
  }

  /** converts an int tree token type to a name.
      Does this by reflecting on nsdidl.IDLTreeTokenTypes,
      and is dependent on how ANTLR 2.00 outputs that class. */
  public static String getNameForType(int t) {
    try{
      Class c = Class.forName(tokenVocabulary);
      Field[] fields = c.getDeclaredFields();
      if(t-2 < fields.length)
        return fields[t-2].getName();
    } catch (Exception e) { System.out.println(e); }
    return "unfoundtype: " + t;
  }


  /** set up reverse links between this node and its first
     child and its first sibling, and link those as well */
  public void doubleLink() {
    TNode right = (TNode)getNextSibling();
    if(right != null) {
      right.left = this;
      right.doubleLink();
    }
    TNode down = (TNode)getFirstChild();
    if(down != null) {
      down.up = this;
      down.doubleLink();
    }
  }

  /** find first parent of the given type,
    return null on failure */
  public TNode parentOfType(int type) {
    if(up == null) {
      if(left == null)
        return null;
      else
        return left.parentOfType(type);
    }
    if(up.getType() == type)
      return up;
    return up.parentOfType(type);
  }

  /** find the first child of the node 
    of the given type, return null on failure */
  public TNode firstChildOfType(int type) {
    TNode down = (TNode)getFirstChild();
    if(down == null) 
      return null;
    if(down.getType() == type)
      return down;
    return down.firstSiblingOfType(type);
  }

  /** find the first sibling of the node 
    of the given type, return null on failure */
  public TNode firstSiblingOfType(int type) {
    TNode right = (TNode)getNextSibling();
    if(right == null) 
      return null;
    if(right.getType() == type)
      return right;
    return right.firstSiblingOfType(type);
  }

}